/Engine/Source/Runtime/Engine/Public/Streaming/LevelStreamingDelegates.h
Called when a streaming level enters a new state. When a level is newly added to the streaming system, PreviousState and NewState may be equal.
static [TMulticastDelegate](API\Runtime\Core\Delegates\TMulticastDelegate)< void([UWorld](API\Runtime\Engine\Engine\UWorld) *, const [ULevelStreaming](API\Runtime\Engine\Engine\ULevelStreaming) *, [ULevel](API\Runtime\Engine\Engine\ULevel) *LevelIfLoaded, ELevelStreamingState PreviousState, ELevelStreamingState NewState)> OnLevelStreamingStateChanged;